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Brel & Kjr

TRANSDUCERSAND CONDITIONING

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CONTENTS

Brel & Kjr Transducers ................................................................................................................................... 1

Top Quality...................................................................................................................................................... 1

Development and Production of Brel & Kjr Transducers ........................................................................... 1

Implementation of TEDS................................................................................................................................. 2

Ordering Transducers ..................................................................................................................................... 3

Customisation ................................................................................................................................................. 4

A Heritage of Excellence................................................................................................................................. 5

Transducer Applications ...................................................................................................................................... 7

Transducers for Aerospace and Defence Solutions ....................................................................................... 8

Transducers for Automotive/Ground Vehicle Solutions ................................................................................ 10

Transducers for Telecom and Audio Solutions ............................................................................................. 12

Selecting the Right Microphone ........................................................................................................................ 15

Microphones ...................................................................................................................................................... 19

Definition of Given Microphone Standards ................................................................................................... 19

Free-field Microphones ................................................................................................................................. 19

Pressure-field Microphones .......................................................................................................................... 22

Array Microphones........................................................................................................................................ 24 Low-noise Microphones ................................................................................................................................ 25

Special Transducers ......................................................................................................................................... 28

Transducers for Sound Intensity Analysis..................................................................................................... 29

Microphones for High-intensity Testing......................................................................................................... 31

Hydrophones................................................................................................................................................. 32

Microphone Preamplifiers ................................................................................................................................. 34

Brel & Kjr Range of Microphone Preamplifiers ........................................................................................ 34

Replacing Discontinued Brel & Kjr Preamplifiers..................................................................................... 37

Microphone Calibration ..................................................................................................................................... 38

Calibrators..................................................................................................................................................... 38 More About Microphones .................................................................................................................................. 41

TEDS Microphones....................................................................................................................................... 41

Microphone Verification and Calibration ....................................................................................................... 43

Microphone & Preamplifier Extension Cables ................................................................................................... 44

Raw Cables................................................................................................................................................... 47

More About Cables ....................................................................................................................................... 48

Microphone Accessories ................................................................................................................................... 49

Adaptors........................................................................................................................................................ 49

Windscreens ................................................................................................................................................. 50

Nose Cones .................................................................................................................................................. 51

Outdoor Protection........................................................................................................................................ 52

Preamplifier Holders ..................................................................................................................................... 52

Corrector ....................................................................................................................................................... 53

Tripods .......................................................................................................................................................... 53

Microphone Comparison Table.......................................................................................................................... 55

Selecting the Right Coupler .............................................................................................................................. 57

Couplers ............................................................................................................................................................ 60

Artificial Ears and Mastoids........................................................................................................................... 60

Ear and Mouth Simulators for Telephone Testing ........................................................................................ 64

Head and Torso Simulators and Telephone Test Heads.............................................................................. 66

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Acoustic Test Accessories............................................................................................................................ 69

Selecting the Right Accelerometer .................................................................................................................... 73

Accelerometers ................................................................................................................................................. 76

Definitions of Given Accelerometer Specifications ....................................................................................... 76

Uniaxial Piezoelectric Charge Accelerometers ............................................................................................. 76

Triaxial Piezoelectric Charge Accelerometers .............................................................................................. 79 Uniaxial CCLD Accelerometers .................................................................................................................... 79

Triaxial CCLD/IEPE Accelerometers ............................................................................................................ 84

Amplified Piezoresistive Accelerometers ...................................................................................................... 86

Industrial Accelerometers ............................................................................................................................. 87

Force Transducers and Impact Hammers ........................................................................................................ 88

Force Transducers........................................................................................................................................ 88

Impedance Heads......................................................................................................................................... 89

Impact Hammers........................................................................................................................................... 90

Non-contact Transducers .................................................................................................................................. 91

Non-contact Transducers for Speed, Velocity and Displacement................................................................. 91

Accelerometer Mounting Solutions ................................................................................................................... 92

Mounting Considerations .............................................................................................................................. 92

Accelerometer Cables ....................................................................................................................................... 94

Brel& Kjr Cables ...................................................................................................................................... 94

Coaxial Cable Assemblies for Uniaxial Accelerometers ............................................................................... 95

Coaxial Cable Assemblies for Triaxial Accelerometers ................................................................................ 99

Cable Assemblies for Industrial and Monitoring Applications ..................................................................... 101

Cable Accessories ...................................................................................................................................... 103

Raw Cables................................................................................................................................................. 104

Accelerometer Accessories ............................................................................................................................ 107

Clip Mounting.............................................................................................................................................. 107 Mounting Blocks and Brackets.................................................................................................................... 109

Other Accessories....................................................................................................................................... 111

Accelerometer Calibration ............................................................................................................................... 117

Reference Accelerometers ......................................................................................................................... 117

Calibrators and Calibration Systems........................................................................................................... 118

Vibration and Shock Calibration Exciters.................................................................................................... 119

Calibration Accessories .............................................................................................................................. 119

Charge Accelerometer Comparison Tables..................................................................................................... 121

CCLD Accelerometer Comparison Tables....................................................................................................... 123

Piezoresistive Accelerometer Comparison Table ............................................................................................ 129

Signal Conditioning ......................................................................................................................................... 131

Multi-pin Signal Conditioners for Microphones ........................................................................................... 131

CCLD Signal Conditioners for Microphones and Accelerometers .............................................................. 132

Charge Signal Conditioners for Accelerometers......................................................................................... 134

What are the Benefits of Signal Conditioning? ........................................................................................... 136

Calibration Systems ........................................................................................................................................ 139

Primary Calibration Systems....................................................................................................................... 139

Secondary Calibration................................................................................................................................. 140

Brel & Kjr Service ....................................................................................................................................... 141

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Brel & Kjr Calibration and Repair Services ............................................................................................ 141

Calibration of Reference Equipment ........................................................................................................... 141

Accredited Calibration................................................................................................................................. 142

Traceable Calibration.................................................................................................................................. 142

Regular Calibration ..................................................................................................................................... 142

Service Agreements.................................................................................................................................... 142

Rentals........................................................................................................................................................ 142 Learn More.................................................................................................................................................. 142

Compliance with Standards ............................................................................................................................ 143

General Compliance ................................................................................................................................... 143

Relevant Microphone Standards................................................................................................................. 143

Dimensions ..................................................................................................................................................... 144

Microphone Dimensions ............................................................................................................................. 144

Accelerometer Dimensions ......................................................................................................................... 147

Glossary of Terms ........................................................................................................................................... 152

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BREL & KJR TRANSDUCERSTransducers have been a core part of Brel & Kjrs business

for more than 70 years. The quality of our transducers is world

renowned and is the result of our unique experience and

knowledge, backed up by meticulous testing and quality control,

which ensures that you get the performance and durability you

expect.

To Brel & Kjr, quality is not measured by product

performance or durability alone. We also strive to provide

excellent support to our customers throughout the relationship,

from initial enquiry to after-sales services. We take pride in

providing the entire measurement chain from the tiniest

accessory to whole systems and solutions.

Top Quality

In all aspects of sound and vibration there are challenges to be

met. For example, making sure that the car that one takes to

work each day can withstand the mechanical shocks imposed

on it, demands measurements of accuracy and precision. This

requires instruments with the performance and quality to match.

All our products are thoroughly tested, often in the harshest

environmental conditions. Extremely high standards are met in

all aspects of product and service provision, as reflected in our

status as an ISO 9001 certified company. Legislation also sets

exacting standards. This often means documented results that

are traceable to known sources, such as a national calibration

laboratory. And naturally, the support customers receive must

always be the most reliable.

Development and Production of Brel & Kjr Transducers

Based on input from our customers, their requirements, and ourown product development plans, we determine the specification

of a new transducer. Initially, analytical tools including a finite

element model (FEM) and other simulation tools based on our

decades of experience are created. From these models we can

begin to optimise the performance of the new design. The

models reduce development time so the first units reach

customers faster with the specified performance.

Engineers discussing a finite element model (FEM)

Testing and VerificationModels can only take the design so far. Brel & Kjr also has

decades of design and manufacturing experience to draw on in

creating transducers of the best value with excellent long-term

stability. Following verification of the mathematical model, the

next step in the development of a new transducer is to construct

several prototypes. In addition to testing and verifying against

the FEM, each prototype is also subjected to:

Environmental testing heat, humidity, etc.

EMC (electromagnetic compatibility)

Base strain

Measurement accuracy

Destructive testing

Electrostatic discharge immunity test as part of EMC testing

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There are many external inputs that can cause measurement

errors in a transducer and affect the accuracy of the

measurement. Therefore, it is extremely important to know how

sensitive each type of transducer is to these external

parameters. The sensitivity to unwanted external sources can

only be accurately determined using advanced testing

techniques and Brel & Kjr has developed its own testing

equipment for this purpose. Of course, each design will have itsown unique response to external environmental factors. We

document each designs sensitivity to its environmental and

more in our detailed Product Data sheets. Understanding how to

make good measurements is where we add value, we have a

support engineer available by phone, on the web or in person to

answer your question and share best practices. Additionally, we

have a wealth of information in our Transducer Handbooks,

Application Notes and Technical Reviews, all available at

www.bksv.com.

Production Test, Test and Test Again!Ongoing testing, verification, and artificial aging ensure that the

quality of the manufactured product is always maintained.

Every Brel & Kjr transducer is thoroughly tested during its

production to ensure that its performance is within the specified

parameters on the Data Sheet. Extremely high standards are

met in our production quality and this is reflected in our status as

an ISO 9001 and EN 9100 certified company. Depending on the

type, a transducer can be subjected to between five and ten

separate test procedures.

If any problems are detected during normal production

verification, we have extensive in-house test equipment

including:

EMC

Climatic testing Base bending

Shock, etc.

This gives our engineers the tools to quickly identify the root

cause, fix the underlying problem and resume normal

production to make timely delivery with the quality you expect

from Brel& Kjr

Final CalibrationAn individual calibration is performed on each microphone and

accelerometer during production or in our calibration laboratory.

Although a frequency calibration at a limited number of

frequencies is easier to perform and simpler to documenttraceablity back to a national standard, our experience is that a

modern calibration technique based on FFT analysis provides

the resolution needed to detect certain types of problems. Our

unique status as not only a manufacturer of transducers but also

the primary Danish standards labs reduces our traceability steps

back to a primary standard which reduces the uncertainty in our

calibrations.

Implementation of TEDS

A wide range of TEDS (Transducer Electronic Data Sheet)

transducers are available from Brel & Kjr. TEDS is

standardised by the Institute of Electrical and ElectronicsEngineers (IEEE) and is supported by many front-ends and

conditioning amplifiers including Brel & Kjrs PULSE LAN-XI

data acquisition, VC-LAN Vibration Controllers, the NEXUS line

of conditioning amplifiers, the 16-channel Conditioning Amplifier

Type 2694 and many more.

TEDS offers a number of benefits:

Plug and play facilities

Type, S/N, sensitivity and more read in directly from the

transducer

Significantly reduced setup time

Practical elimination of cable routing errors

How Does TEDS Work?Basically the chip containing the TEDS data and TEDS interface is

built into the transducer. TEDS data is updated during the

measurement systems boot sequence or whenever update

TEDS is activated.

TEDS data can be transmitted to the front-end in two different ways:

Class I TEDS: On the same wire as the analogue signal

Class II TEDS: Via a separate wire

Class I is always used with CCLD transducers since TEDS can

be implemented using the traditional coaxial cable.

For measuring microphones, either Class I or Class II can be

used depending on the preamplifier, where the actual TEDS

chip is located. When Class II is used, pin 5 (often denoted as

No connection in earlier product data) is used to transmit the

TEDS data. This is important when using extension cables as

some older cables might really not have pin 5 connected, which

will break the TEDS chain.

The TEDS microphone and preamplifier bundles are assembled under

controlled conditions, which means that special precautions are

taken to avoid dust and contamination entering the boundary

between microphone cartridge and the preamplifier. This is

important in order to maintain low noise even at hightemperatures and high relative humidity. It is also important that

when TEDS, Class I or II, is used with microphones that the

microphone stays with the preamplifier it was programmed with

since the preamplifier is where the TEDS information of the

specific microphone is actually stored. To avoid this error, many

Brel & Kjr microphones are permanently connected to their

preamplifiers
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Example of Class I TEDS transducer as used in a DeltaTron

TEDS microphone

Example of Class II TEDS as used in a TEDS microphone

The IEEE 1451.4 StandardCurrently the version programmed and the actual chip used to

store the transducers TEDS information is in transition. Most

sound and vibration transducers (Brel & Kjr as well as other

manufacturers) conform to IEEEP1451.4 V.0.9 which is actually

a standard proposal and differs slightly from the final standard

IEEE 1451 V.1.0.

Re-mapping to IEEE 1451V.1.0 is available for all Brel & Kjr

transducers at time of order or as part of after-sales service.

Relevant Brel & Kjr hardware (PULSE, NEXUS, etc.) supportboth the proposed and final version of the standard, and in

many applications the user will not notice a difference between

the two standards. The major difference between the proposed

and final version concerns the memory map. In the proposed

version, all data is in a R/W area of the memory, while in V.1.0

some permanent data (manufacturer, etc.) has been moved to a

write once area of the memory. This leaves more space in the

user area of the memory.

Currently, Array Microphone Types 4957, 4958 and 4959 are

supplied with TEDS according to the final revision

IEEE 1451.4V.1.0.

TEDS TemplatesThe TEDS template defines the memory mapping of the TEDS

chip and hence the understanding between transducer and front-

end.

A number of TEDS templates have been standardised by the

IEEE and in addition to this, a number of non-standard vendor

specific templates exist. The different TEDS templates are

differentiated by different ID numbers.

See TEDS Microphonesfor a listing of the templates used with

Brel & Kjr microphones and preamplifiers.

Ordering Transducers

To order from Brel & Kjr, you just need to know an items

order number. For transducers and signal conditioners, these

will be a number preceded by the word Type. For example:

1/2-inch Prepolarized Microphone Type 4188

Miniature Triaxial DeltaTron Accelerometer Type 4520

Charge to DeltaTron Converter Type 2647

A transducer may have several models that vary from each

other (different sensitivity, interface or accessories). This is

denoted by a letter after the number, by a dash (-) and threealphanumeric characters, or a combination of a letter and then

three alphanumeric characters, for example:

Charge to DeltaTron Converter Types 2647-A, 2647-B and

2647-C

Miniature Triaxial DeltaTron Accelerometer Types 4520-001

and 4502-004

1/2-inch Free-field Microphone including High-temperature

Preamplifier Type 1706 with TEDS Type 4189-H-041

There are some general rules within transducer families relating

to the letter:

For CCLD accelerometers, a B in the type number

indicates that the transducer contains TEDS

For microphones:

A or H in the type number indicates a CCLD

preamplifier with TEDS

B, C, or L in the type number indicates a 7-pin

LEMO preamplifier with TEDS

For accessories, the order number is an alphanumeric code

starting with two letters. For example:

AO-xxxx: Extension Cables

UA-xxxx: Adaptor and Mounting Clips

YM-xxxx: Adhesive Mounting Pads

YJ-xxxx: Glue and Adhesives

QS-xxxx: Glue and Adhesives

Each transducer has a Product Data sheet (PD) with ordering

information including all required accessories. You can find

transducer PDs on www.bksv.com.

TEDS TEDS

060215

CCLD

Signal

Typical Class l TEDS

Microphone

DeltaTron

Input

--

TEDS

+Vcc

-Vcc

+Vcc

-Vcc

Pol Voltage

CIC Signal

TEDS Data

Signal

1

2

3

4

5

6

7

7-pin LEMO

Typical Class ll TEDS

Microphone

Classical Microphone

Input060214

GND
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Customisation

Despite the large number of transducers available in

Brel & Kjrs standard selection, special measurement

situations can occur requiring a transducer that cannot be met

by our standard product range. In order to effectively meet our

customers needs, we offer customised products.

We already have a broad portfolio of non-standard products

developed for special applications. For further details on what

Brel & Kjr can offer for special applications, please contact

your local representative.

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Milestones in Brel & Kjr Accelerometer History

Worlds first commercial piezoelectric accelerometer made from

Rochelle salt crystals and developed by Dr. Per V. Brel

Brel & Kjr s first lead zirconate titanate (PZT) accelerometer

Brel & Kjr s standard reference accelerometer based on an inverted,

centre-mounted compression design with quartz crystal piezoelectric

element, ensured a high degree of accuracy for calibration

This all-titanium accelerometer was the first based on Brel & Kjrs

patented DELTASHEAR

design. Still in use today, the construction isregarded as one of the all-time, classic accelerometer constructions

The first miniature accelerometer with a PlanarShear design -

extending the frequency range of Brel & Kjr Shear design

Worlds first accelerometer with constant voltage line-drive (CVLD)

built-in preamplifier

Brel & Kjr s first and highly reliable industrial DELTASHEARaccelerometer suitable for permanent vibration monitoring in potentially

explosive environments

Worlds first dedicated modal shear accelerometer family

The worlds first ORTHOSHEARtriaxial accelerometer - one seismic

mass for optimized noise floor and orthogonality

Another world first - an accelerometer with integrated TEDS

(Transducer Electronic Data Sheet)

The first miniature triaxial accelerometer with integrated TEDS

A THETASHEAR, CCLD accelerometer for applications up to 180C

(356F) the highest temperature for an accelerometer with built-inpreamplifier in the industry

Wide temperature range (321 to +900 F (196 to +482C)) industrial

accelerometer with superior temperature transient performance from

Shear design

This universal CCLD triaxial accelerometer never sits still on the shelf,

and has the widest temperature and dynamic range

Brel & Kjr becomes AS/EN9100 certified within the scope of

development, production and service of customer-specific accelerometers

1943

1957

1971

1974

1977

1985

1985

1996

1998

1999

2005

2008

2012

Type 4301

Type 4310

Type 8305

Type 4366

Type 4374

Type 4390

Type 8317

Types 4507

and 4508

Type 4506

Type 4507-B

Type 4524-B

Type 4526

Type 8347-C

Type 4527

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TRANSDUCER APPLICATIONS

Brel & Kjr supplies integrated solutions for the measurement

and analysis of sound and vibration. As a world-leader in sound

and vibration measurement and analysis, we use our core

competences to help industry and governments solve their

sound and vibration challenges so they can concentrate on their

primary task: efficiency in commerce and administration.

The Complete SolutionWe are unique in the industry in producing all of the elements for

complete sound and vibration test systems. Our goal is to create

the most technologically advanced components, built to the

highest quality and designed to save time and eliminate errors in

the measurement process. We have an unequalled product

range, but our real advantage lies within our ability to supply a

complete solution.

Not only do the individual components meet the highest

performance standards in the industry, they are also designed to

interact and communicate with each other to provide unrivalled

measurement security and user feedback. This allows us to

create solutions that are targeted at optimising your workprocesses, to provide rapid, reliable results.

As the sound and vibration challenges facing industry are

diverse from traffic or airport noise, vibration in a car engine,

evaluation of building acoustics, cabin comfort in a passenger

airplane to production quality control or wind turbine noise, we

have over the years developed creative and technically

advanced solutions to innumerable customer problems. Some of

the work we have done with customers is published as case

studies.

Transducers in the Measurement Chain

Transducers are the vital first lik in your measurement chain. Asthey stand on the front line and provide you with the raw data

you need, it is critically important that they are trustworthy.

Brel & Kjr has always set the standard that others have tried

to follow and offers the industrys largest selection of

transducers, to help you make the most accurate measurements

possible.

In the following pages, you can learn about how Brel & Kjrs

wide range of transducers can be applied in such disparate

fields such as Aerospace and Defence, Automotive/Ground

Vehicles and Telecom/Audio.
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Ever-shortening design and development timeframes of modern

aerospace and space programs demand 'right-first-time'

engineering. The aerospace sector is seriously contemplating

aviation efficiency and environmental issues, whilst defence

industries have the added concerns of ensuring reliability and highperformance of military systems, often under extreme conditions.

Recognising that high quality, goal-focused, time- and cost-efficient

testing is critical to meeting program milestones, Brel & Kjr

addresses today's engineering needs by providing quality sensor

solutions.

Whether turnkey solutions or dual-use application needs,

Brel & Kjr provides the aerospace and defence sectors with

transducers that comply with common industry standards such as:

BS EN ISO 9001:2008

EN 9100:2009 AS 9100 Rev. C

Brel & Kjrs quality management system is applicable to:

development, production, sales and service of customer-specific

transducers.

Transducers for Aerospace and Defence Solutions

Acoustic Test SuiteWhether your interest is exterior or interior

noise, our acoustic test suite provides

data acquisition and assessment systems

to combat your noise problems byoptimising noise performance, improving

sound quality, and ensuring compliance

with environmental legislation.

Noise source mapping and location

Wind tunnel and flight testing

Engine and aircraft certification

Acoustic material testing

Cabin comfort and occupational health

Ramp noise and sonic boom

Underwater acoustics

Hull monitoring

Acoustic stealth and noise signature

management

4938-A-011

8103, 81048105, 8106

4961

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Environmental Test SuiteReproducing realistic operational

conditions in the laboratory is essential for

qualifying the real-life integrity of

structures to ensure durability. Whetherfor billion-dollar satellites, launchers,

aircraft, instruments or structures, our

comprehensive vibration test solutions

provide a wealth of environmental test

systems.

Durability and acoustic fatigue testing

Classical and pyro shock

Sine, random, sine-on-random,

random-on-random testing

Shock response spectrum

Kurtosion

Field data replication

Rotating Test SuiteVibration analysis of rotating machinery

provides valuable information on engine

health, reliability and performance. From

R&D and production testcell applicationsto on-ground maintenance, our vibration

measurement and analysis systems

provide you with powerful machine

analysis tools.

Vibration analysis, monitoring and

diagnostics

Vibration data acquisition and analysis

in engine test cells

On-ground vibration check of aircraft

engines

Order analysis and autotracking

Balancing and trim balancing

HUMS transducers

Structural Test SuiteStructural dynamics testing is vital to

understand and optimise the inherent

dynamic properties of structures, to

ensure reliable and safe operation. Ourstructural test suite offers complete

systems for controlled excitation testing,

real-life operational testing and test-FEA

integration from the smallest

components to the largest assembled

structures.

Operating Deflection Shapes analysis

Operational Modal Analysis

Classical Modal Analysis

Normal mode testing

Structural dynamics modifications

Model correlation and updating

83394517

4948

4573-D

4574-D

4944

8347-C

4393

4505-A

1702

4523

Model of atotal airplaneduring modalanalysis

4507-B

4524-B

4511-001

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Passenger vehicles such as cars, trucks, motorcycles, buses

and trains continuously need to be more exciting and pleasant,

while becoming safer and emitting less noise. This makes Noise,

Vibration and Harshness (NVH) testing a key to competitive

advantages for vehicle manufacturers.

Brel & Kjr's expert knowledge of the industry, combined with

extensive experience of customer-driven projects, allows us to

cover the whole vehicle NVH development process. Our

solutions range from vehicle NVH simulators for target setting, to

spherical beamforming for 360-degree noise mapping.

We provide a wide range of engineeringservices to improve products or executecomplete development programmes, incooperation with global partners.

Transducers for Automotive/Ground Vehicle Solutions

Interior NVHTime Domain SPC enables engineers to

calculate, listen to, and modify individual

contributions to the vehicle occupants

(both airborne and structure-borne), andassists with design and validation of

programme NVH targets.

Sound EngineeringThe NVH Simulator Suite auralises NVH

data with advanced sound-simulation

techniques, allowing you to efficiently

communicate NVH targets to non-experts

even before physical prototypes are

available. The On-road Simulator allows

evaluation of virtual vehicles, and even

benchmarking of competitive vehicles

under real driving conditions.

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Powertrain TestingBrel & Kjr provides tools for effi-

cient powertrain testing:

Very high-temperature triaxial accel-erometers

Crankshaft angle analysis software

Systems for measuring sound power

versus RPM

Holography systems for locating noise

sources and measuring partial sound

power versus RPM and crank angle

Wide band noise source identification

systems customised to fit engine test

cells

NVH simulators to evaluate powertrain

components or complete powertrains

in full vehicle context

Hybrid-electrical and electrical

vehicles:

Switching noise analysis, transient

analysis, high-frequency beamforming,

multi-field microphone with very low

magnetic sensitivity for measuring in

unknown sound fields

NVH simulator for exterior vehicle

noise Vibration testing of large batteries

Structural AnalysisThe Structural Dynamics Suite helps

improve the dynamic behaviour of any

structure. It includes Operating Deflection

Shapes analysis covering the full set ofmethods (frequency, order, time),

Classical Modal Analysis with a wide

range of powerful curve-fitters, and

Operational Modal Analysis.

Squeak and RattleOur unique equipment range ensures that

automotive components and interiors are

durable and free from noise, and supports

industry-standard QA practices for squeak

and rattle vibration testing.

Low-noise shaker systems

Sound quality analysis software

Array-based systems for quick

localisation of noise sources

Wind Tunnel TestingSurface microphones on the exterior of a

vehicle measure the pressure fluctuations

at different positions, whilst beamformers

placed outside the main airflow pinpointthe location of noise sources and quantify

the relative noise contributions. When

combined with a spherical beamformer

inside the vehicle, a detailed noise cause-

effect relationship is achieved using

minimal testing time.

Exterior NoiseAs community regulations put ever

tighter restrictions on noise emission, our

Vehicle Pass-by solutions offer complete

support to ensure compliance with the

latest standards. Adding moving-sourcebeamforming enables noise source

localisation and troubleshooting during

measurements. Our Indoor Simulated

Pass-by Noise System enables efficient

comparison of design alternatives.

4517

4573-D

4527

4944

49614949-B

2981

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Manufacturers of electroacoustic equipment such as loudspeakers,

microphones, telephones, headsets, hearing aids and

hydrophones deliver successively high-quality acoustical designs

by continuously innovating their products and processes.

Acoustic performance has become increasingly important as users

demand high quality audio in every situation, whether reproducing

sound or transmitting speech. Measuring and documenting the

acoustic performance, therefore, is a key element in the product

improvement process, during both its development and

manufacture.

Brel & Kjr has a long tradition of close connections with the

fields of telecommunications and audio, pioneering many methods

that are now standard practice all over the world.

Today, based on our accumulated knowledge and experience, weoffer a variety of electroacoustic test systems, audio analyzers, and

transducers for electroacoustic applications.

Transducers for Telecom and Audio Solutions

Electroacoustic Test SystemsOur experience of providing quality

acoustic solutions gives us a solid

background when developing new

systems for emerging technologies andmarkets. Our range of dedicated

electroacoustic test systems is eminently

suitable for acoustic design,

benchmarking, prequalification and

conformance testing of mobile phones,

tablets, VoIP phones, headsets,

loudspeakers, etc.

The test system supports the entire

workflow required by typical test

procedures. This covers system

calibration and verification, variousacoustic measurement suites for

evaluating the performance of devices

under testing, and reporting. Tools for

easy comparison of measurements as

well as tools to hear and edit recordings

are also available.

Vibration testing oftelephone

Telephone testhead

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Audio AnalyzersWith PULSE being one of the most

commonly used platforms for conducting

acoustic measurement, it forms a solid

foundation for our audio analyzers. Theseoffer a variety of analysis methods,

covering traditional sine testing (using

SSR and TSR), spectrum analysis (using

FFT and CPB) for testing using real

speech, and perception-based test

methods.

In combination with the dedicated

hardware, this supports the audio

engineer in achieving the acoustic design

goals setup. Besides its measurement

and analysis capabilities, PULSE alsooffers tools to automate test procedures,

as well as reporting and data

management tools for easy archiving and

retrieving of measurement data and

related information.

TransducersTo guarantee reliable acoustic

measurements, most national standards

laboratories use Brel & Kjr reference

microphones. Consequently, mostacoustical measurement in the world

ultimately refers back to Brel & Kjr

products.

A comprehensive portfolio of transducers

supports standardised testing of

telephones, hearing aids, headphones,

headsets, ear phones, loudspeakers,

receivers and many other applications.

Our range of acoustical transducers

includes ear simulators, mouth simulators

and microphones. All transducers

supplied by Brel & Kjr contain

information about their actual sensitivity.

When the transducer is connected to the

analyzer this information is automatically

transferred to the analyzer, ensuring that

the proper setting is always used for the

specific measurement task.

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SELECTING THE RIGHT MICROPHONE

Brel & Kjr offers a broad spectrum of solutions that respond

to varying needs and applications. This adaptability is evident in

the range of transducers designed for specific environments,

industries, tasks and conditions, as well as general purpose

instruments that provide a wide operational range.

Selecting the best transducer for a given measurement task can

be understandably overwhelming. Our interactive transducerselection guide on www.bksv.com can be a big help to quickly

narrow your choices. Alternatively, you can use the Microphone

Matrix below to help you select the right microphone to fit your

needs.

Condenser microphones:

are either externally polarized or prepolarized

come in different sizes: 1-inch, 1/2-inch, 1/4-inch, or 1/8-inch

are optimised for either free-, pressure-, or diffuse-field

For a quick overview, product types are listed according to these

classifications. Microphones that do not directly match one of

these classes are denoted as Special Microphones.

1/8-inch microphones are pressure types. Due to their small

size, the free-field and pressure response are approximately the

same up to quite high frequencies (for example, the free-field

correction is less than 1 dB at 15 kHz).

Mapping Brel & Kjr measurement microphones in the

Microphone Matrix is now a simple task.

The Microphone Matrix

For Selection Consider the Following

Which kind of input module classical or CCLD?

CCLD (including DeltaTron and IEPE) can only work with

prepolarized types; classical input works with both prepolarized

and externally polarized cartridges. For more information about

CCLD and classical input see the preamplifier section. For

portable instruments and where high humidity is present,

prepolarized microphones are preferred. For more general use

in the laboratory or where high temperature is present, the use

of external polarised microphones is recommended.

Does the microphone have to fulfill any specific standard?

If this is the case, see Microphone Standardsin the appendix.

Frequency range and maximum sound pressure level (SPL) will

often determine which microphone size to use.

Generally a smaller microphone has a broader frequency range

and a lower sensitivity. For more details, see Maximum Limits

and Dynamic Range.

For which sound field should the microphone be

optimised*?

For measurements made away from reflecting surfaces, forexample, when making outdoor measurements, or in

acoustically well-damped indoor environments, a free-field

microphone is best. But for measurements made in small closed

couplers, or close to hard surfaces, a pressure-field microphone

is best. For measurements in enclosed areas where

reverberation is likely, microphones optimised for diffuse-field

(random-incidence) response are best. In some cases, pressure

type microphones can also be found to have sufficiently flat

random incidence response. This is because the random

Type of Microphone Type 1/8-inch 1/4-inch 1/2-inch 1-inch Polarization

Free-field

4954

4137

4176418841894950

Prepolarized

493941904191

4145 Externally polarized

Pressure-field

4944

4947494849494953

Prepolarized

413849384941

4192 4144 Externally polarized

Diffuse-field

4942 Prepolarized

4943 Externally polarized

Special

49614958

49484949

Prepolarized

4187, 49574938-WH-1418

4938-W-001

418041934955

41604179

Externally polarized

* Optimised means that the microphone has a flat frequency response in thespecified frequency range of the particular sound field
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incidence response of a pressure-field microphone is much

flatter across the frequency range than that of a microphone

optimised for flat free-field response. A special case is the

measurement of surface pressure where surface microphones

would be the obvious choice.

Special application or condi tion?

For special applications, a special microphone can be selected,for example, laboratory standard microphones, outdoor

microphones, array microphones, infrasound microphones,

etc. If the microphone is to be used in extreme temperature

conditions, see Effects of Temperature for guidance.

Maximum Limits and Dynamic RangeInherent Noise: Even if a microphone is placed in a totally

quiet room there will be some Brownian movement of the

microphone back-plate and diaphragm. These movements

correspond to very small pressure fluctuations and will cause

changes in the cartridge capacity which if a polarisation

voltage is present cause an output voltage from the

microphone. The SPL corresponding to this output voltage isdefined as the inherent noise of the microphone cartridge.

3% Distortion Limit:Even though the condenser microphone

is highly linear, at a certain pressure there will be some

distortion of the output signal. At Brel& Kjr we specify the 3%

distortion limit as a recommended maximum limit for accurate

measurements.

10% Distortion Limit: Increasing the sound pressure behind

the 3% distortion limit will result in a further increase in

distortion. In some cases, a 10% distortion limit is specified. In

many practical cases, the 10% distortion limit is determined by the

preamplifier.

Maximum SPL:Due to mechanical forces acting on the cartridge

there is a maximum pressure level which should never be

exceeded or the long-term stability can be influenced and/or

mechanical damage can happen. The corresponding sound

pressure level is called the maximum SPL.

Dynamic Range of Microphone/Preamplifier Combinations:

In a practical application, the lower limit of dynamic range is

determined by the combined noise from the cartridge and the

preamplifier. The upper SPL limit will often be determined by the

output voltage swing from the preamplifier. This is especially

important when using CCLD preamplifiers, since here the

maximum voltage is limited by the input stage compliance(open-circuit) voltage.

A compliance voltage of, say, 28V as used in many front-ends will

limit the maximum voltage swing to around 14Vppand this may

determine the real maximum limit of a cartridge/ preamplifier

combination.

Brel & Kjr defines the dynamic range as the range from the

noise floor in dBA to the SPL resulting in a 3% distortion limit

with a given cartridge/preamplifier combination, and nominal

compliance voltage where relevant.

The table below shows the maximum SPL as determined by the

preamplifier. However, it must be mentioned that in some cases

the maximum SPL is limited by the cartridge. This is especially

true for classical input using 80 V supply. On the other hand, a

classical input with 14 V supply will reduce the maximum SPL

9 dB compared with 80 V supply.

Maximum measurable SPL in dB for different cartridgesensitivities, rounded to nearest integer value

The general formula is:

Max. SPL in dB = [94 + 20*log(Vmax/Sv)]

where Vmaxis the maximum (3% distortion) RMS output voltage

of the preamplifier and Svis the (loaded) cartridge sensitivity in

V/Pa.

Measuring in Magnetic FieldsWhen performing sound measurements in magnetic fields like:

on a hybrid or electrical car, close to wind turbine generators,

close to big MR scanners or other similar equipment, it may be

beneficial to use the latest Brel & Kjr microphones made out

of titanium, such as Types 4948, 4949, 4955 and 4961. The

titanium is much less susceptible to magnetic fields than metals

normally used in microphones.

The magnetic field impact is seen as noise and is increasing the

noise floor of the microphone. For example:

1/4-inch Array Microphone 4958 has a susceptibility to

magnetic fields corresponding to an equivalent SPL of 40 dB

for an 80 A/m, 50 Hz field

1/2-inch Free-field Microphone Type 4189 has a

susceptibility to magnetic fields corresponding to an

equivalent SPL of 6 dB SPL for an 80 A/m, 50 Hz field

Titanium microphone Types 4955 and 4961 have no

detectable influence from an 80 A/m, 50 Hz magnetic field

The Effects of Temperature

What happens at high temperatures (above +80C)?

Electronic components may exceed their maximum junction

temperature. This is very serious and should be avoided.

Pre-polarized microphones may lose electret voltage.

This will result in permanent sensitivity loss, which means,

externally polarized microphones should always be used if

high temperature tests are performed for longer periods of

time

The diaphragm tension will reduce. This means increased

sensitivity and changes in frequency response

The cable jacket and other isolators may melt. While this is

not beautiful, it is not always catastrophic

CartridgeSensitivity

mV/Pa

CCLD7 VOutput Swing

NEXUS40 V

PULSE14 V

50 134 149 140

31.6 138 153 144

12.5 146 161 152

3 158 173 164

1 168 183 174

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In practically all cases, an exponential increase in the

inherent electronic noise must be expected. The basic rule

of thumb: Many temperature depending factors will double

for every 10 temperature increase (Arrhenius' law)

Microphones are specified at 23C, and have a Temperature

Coefficient which specifies how the microphone will behave with

changed temperature. This parameter tells something about themicrophones stability and quality. See the microphones product

dat for information about its Temperature Coefficient.

General purpose microphones like Type 4189 perform well

within their specifications in the temperature range from 30 to

+150C.

General purpose preamplifiers have a relatively stable DC bias

up to around 80C. They are specified from 20 to +60C (4 to

+140F), but work very well at temperatures of up to +80C

with some increase in noise.

High Temperature Preamplifier Type 1706 is designed toperform up to 125C. At high temperatures, it has a more stable

DC bias point and no reduction of maximum SPL limit. The

electrical noise increases at high temperatures, which affects

the lower limit of the dynamic range of the microphone/

preamplifier combination and limits its ability to measure very

low sound pressure levels.

In regards to the use of cables in high temperatures, you should

note that PUR cables are not recommended. Consider silicone

cables, which are rated at 150C or PFA cables which function

from 75 to +250C, like cable AO-0406.

What if it gets real ho t (+125C)?

You must get the preamplifier away from the hot spot

Flush Mounting Kits UA-0122, UA-0123 or Swan NeckUA-0196 are good tools to use

Sometimes Probe Microphone Type 4182 will do the job

Probe Microphone Type 4182 allows sound pressure

measurements to be made in small or awkward places or in

harsh environments with high temperatures (up to 700C). The

probe microphone has a smooth frequency response from 1 Hz

to 20 kHz, with a very smooth high-frequency roll-off.

Measurements can be performed extremely close to the sound

source due to its small size. Measurement points can be closely

spaced when it is necessary to have high spatial resolution. The

static pressure inside the probe microphone can be equalized to

that of the measurement site.

Measuring in extremely cold temperatures (160C)

Type 4944-W-005 is a special microphone that is designed to

handle measurements down to 180C, which is perfect for use

in, for example, cryogenic wind tunnels.

++

Type2671-W-001

20 to +125C

( 4 to +257F)

3 to 50 Hz

20 to +80C

( 4 to +176F)

3 to 50 Hz

30 to +150C

( 22 to +302F)

6.3 to 20 kHz15.2 to 146 dB

30 to +150C

( 22 to +302F)

3.15 to 20 kHz15 to 148 dB

30 to +250C

( 22 to +482F)

3.15 to 40 kHz21.4 to 162 dB

55 to +100C

( 67 to +212F)

5 to 20 kHz55 to 160 dB

180 to +100C

( 292 to +212F)

16 to 70 kHz48 to 169 dB

10 to +700C

(+14 to 1292F)

1 to 20 kHz42 to 164 dB

Type1706

Type4189

UA-0196with

Type4190

UA-0123with

Type4192

Type4948

Type4944-W-005

Type4182

200C / 328F

100C / 148F

0C / 32F

100C / 212F

200C / 392F

300C / 572F

400C / 752F

500C / 932F

600C / 1112F

700C / 1292F

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Replacement of Discontinued Brel & KjrMicrophonesMost present Brel & Kjr microphones are Falcon Range

microphones. The Falcon Range line offers a number of

advantages, for example, the diaphragm mounting method (press

fit mounted or laser welded) that provides a higher mechanical

robustness. Furthermore, the use of a stainless steel diaphragmresults in an improved resistance to environmental conditions.

The table can be helpful if you need to replace an older

Brel & Kjr type.

Older Types of Microp honeRecommended Replacement

Microphone Types

4133 4191

4134 4192

4135 4939

4136 4938

4147 4193

4155 4189

4165 4190

4166 4943

4196/4935 4957

4951 4958

4181 4197
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Type No. 4190 4191 4950 4145

Diameter inch 1/2 1/2 1/2 1

Optimised Free-field Free-field Free-field Free-field

Standards B, I, L B, I, L, M I, K A, I

Nominal Open-circuit Sensitivit y mV/Pa 50 12.5 50 50

Polarization Voltage* V 200 200 0 200

Optimised Frequency Response 2 dB Hz 3.15 to 20000 3.15 to 40000 4 to 16 kHz 2.6 to 18000

Dynamic Range with Preamplifier(Preamplifier type number)

dB(A) to dB15 to 148

(2669)21.4 to 162

(2669)14 to 142

(2669)10.2 to 146

(2669)

Inherent Noise dB (A) 14.5 20 13.5 10

Capacitance pF 16 18 12.5 66

Venting Rear Side Rear Rear

Lower Limiting Frequency (3 d B) Hz 1 to 2 1 to 2 0.5 to 5 1 to 2

Operating Temperature Range C 30 to 150 30 to 300 30 to 100 30 to 100

Temperature Coefficient dB/C 0.007 0.002 + 0.006 0.002

Pressure Coefficient dB/kPa 0.01 0.007 0.02 0.015

* 0 V = Prepolarized microphone
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Diffuse-field Microphones

A diffuse-field microphone, also called a random-incidence

microphone, is designed to have a flat response when signals

arrive simultaneously from all directions. They should, therefore,

not only be used for making measurements in reverberation

chambers, but also in all situations where the sound field is

diffuse, or where several sources contribute to the sound pressure

at the measurement position. Examples include indoor

measurements where the sound is reflected by walls, ceilings,

and objects in the room, or measurements made inside a car.

Type No. 4942 4943

Diameter inch 1/2 1/2

Optimised Diffuse-field Diffuse-field

Standards K K

Nominal Open-circuit Sensitivity mV/Pa 50 50

Polarization Voltage* V 0 200

Optimised Frequency Response 2 dB Hz 6.3 to 16000 3.15 to 10000


dB(A) to dB 15.2 to 146(2669)

15.9 to 148(2669)

Inherent Nois e dB (A) 14.6 15.5

Capacitance pF 13 16

Venting Rear Rear

Lower Limiting Frequency (3 d B) Hz 2 to 4 1 to 2

Operating Temperature Range C 40 to 150 40 to 150

Temperature Coefficient dB/C 0.001 0.010

Pressure Coefficient dB/kPa 0.01 0.008

Preamplifier Included No No


In many cases, the pressure- and diffuse-field responses will

both be within 2 dB up to a certain frequency. The graphshows that for Type 4943, both responses are within 2 dB

up to 10 kHz
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Pressure-field Microphones

A pressure-field microphone is best suited for measurement of

the sound pressure in a small closed couplers or close to hard

reflective surfaces. A special class of pressure microphones is

Brel & Kjrs surface microphone, which due to its unique

geometrical dimensions, can be mounted directly on surfaces

such as the skin of an airplane or the surface of a car, for easy

measurement of the true pressure fluctuations.

Type No. 4138 4938* 4944 4947 4192 4144

Diameter inch 1/8 1/4 1/4 1/2 1/2 1

Optimised Pressure-field Pressure-field Pressure-field Pressure-field Pressure-field Pressure-fie ld

Standards F F K E, K, M D, L

Nominal Open-circuit Sensitivit y mV/Pa 1 1.6 1 12.5 12.5 50

Polarization Voltage V 200 200 0 0 200 200

Optimised Frequency Response 2 dB Hz 6.5 to 140000 4 to 70000 4 to 70000 8 to 10000 3.15 to 20000 2.6 to 8000


dB(A) to dB

52.2 to 168

(2670 +UA-0160)

42 to 172(2670)

46 to 170(2670)

21.4 to 160(2669)

20.7 to 162(2669)

11 to 146(2669)

Inherent Noise dB (A) 43 30 30 17.5 19 9.5

Capacitance pF 3.5 6.1 5 14 18 55

Venting Side Side Side Rear Side Side

Lower Limiting Frequency (3dB) Hz 0.5 to 5 0.3 to 3 0.3 to 3 1 to 5 1 to 2 1 to 2

Operating Temperature Range C 30 to 100 40 to 150 40 to 150 30 to 125 30 to 150 30 to 100

Temperature Coefficient dB/C 0.01 + 0.003 + 0.008 + 0.006 0.002 0.003

Pressure Coefficient dB/kPa 0.01 0.003 0.003 0.006 0.005 0.016

Preamplifier Included No No No No No No

* Type 4938-W-001 is optimised for high static pressure 0 V = Prepolarized microphone

Type No. 4948 4948-A 4948-B 4949 4949-B 4953

Diaphragm inch 0.41 0.41 0.41 0.41 0.41

OptimisedSurface

PressureSurface

PressureSurfacePressure

SurfacePressure

SurfacePressure

Pressure

Standards

Nominal Open-circuit Sensitivit y mV/Pa 1.4 1.4 1.4 11.2 11.2 50

Polarization Voltage* V 0 0 0 0 0 0

Optimised Frequency Response 3 dB Hz 5 to 20000 5 to 20000 5 to 20000 5 to 20000 5 to 20000 1 to 12000


dB(A) to dB 55 to 160 55 to 160 55 to 160 30 to 140 30 to 14016.2 146

(2669)

Inherent Noise dB (A) 55 (typical) 55 (typical) 55 (typical) 30 (typical) 30 (typical) 15.7

Capacitance pF N/A N/A N/A N/A N/A 14.6

Venting Front Front Front Front Front Rear

Lower Limiting Frequency (3dB) Hz 1 to 5 1 to 5 1 to 5 0.5 to 5 0.5 to 5 1 2.4

Operating Temperature Range C 55 to 100 55 to 100 55 to 100 30 to 100 30 to 100 30 to 150

Temperature Coefficient dB/C 0.013 0.013 0.013 0.013 0.013 0.006

Pressure Coefficient dB/kPa 0.007 0.007 0.007 0.007 0.007 0.008

Preamplifier Included CCLD CCLD CCLD CCLD CCLD N/A

TEDS UTID 769 769 769 769 769 N/A

CIC No Yes Yes No Yes N/A

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Multi-field Microphone

Multi-field microphones are ideal for any situation in which the

nature of the sound field is unpredictable, or the direction of the

dominant noise source is difficult to pinpoint or shifts over time.

Brel & Kjrs Multi-field Microphone Type 4961 is the worlds

first 1/4-inch condenser microphone with a 20 dB(A) noise floor,

60 mV/Pa sensitivity and a maximum SPL of 130 dB the same

basic performance you would expect from a conventional 1/

2-inch condenser microphone. It guarantees that your

measurements are accurate in free or diffuse sound fields and

at any angle of incidence.

Manufacturing and StabilityThe microphone and preamplifiers all-titanium construction

ensures maximum resistance to corrosion. This means that you

will never have to worry about pinholes in the microphones

diaphragm a common problem with nickel foil diaphragms.And titaniums insensitivity to magnetic fields means that you do

not have to worry about interference from electromagnetic

sources.

Type No. 4961

Diameter inch 1/4

Optimised Multi-fieldStandards

Nominal Open-circuit Sensitivity mV/Pa 65

Polarization Voltage V 0

Optimised Frequency Response 2d B Hz 12 to 20000

Dynamic Range with Preamplifier dB(A) to dB 20 to 130

Inherent Nois e dB (A) 20

Capacitance pF N/A

Venting Side

Lower Limiting Frequency (3 dB) Hz 3 to 6

Operating Temperature Range C 20 to + 80C

Temperature Coefficient dB/C 0.01

Pressure Coefficient dB/kPa 0.013

Preamplifier Included CCLD

TEDS UTID 769

Connector SMB

Small Microphone,Big Performance

Because Type 4961 is so small and relatively insensitive to

the angle of incidence, its response is uniform (even at high

frequencies) in virtually any sound field.

It is very easy to position when setting up measurements

technicians can simply place it where they want to measureand save valuable time.

Well-suited for complex spaces with non-stationary or multiple

sources that need to be measured in one go, Type 4961 is

ideal for the automotive or aerospace industries, for example,

during in-cabin noise measurements. In effect, a single multi-

field microphone can cover many measuring scenarios that

would otherwise require three different conventional 1/2-inch

microphones.
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Array Microphones

Array-based measurement techniques allow you to quickly map

the sound intensity from a number of points across a source.

Brel & Kjr provides a wide selection of arrays to cover most

measurement situations including acoustic holography and

beamforming, as well as the microphones best suited for use in

these systems.

Type 4957is an economy type with only basic TEDS and a

limited frequency range, but a higher sensitivity

Type 4958is a precision type with intelligent TEDS, that is,

TEDS that contains polynomial coefficients describing the

complex transfer function of the microphone. This

information can be used in the array application in order to

increase sharpness and precision

Type 4959 is a very short microphone for hand-held and

foldable arrays

Note that both Types 4944-A and 4954-A can be used with

arrays as well.

Type No. 4957 4958 4959

Diameter inch 1/4 1/4 1/4

Optimised Array Array Array

Standards

Nominal Open-circuit Sensitivit y mV/Pa 17 17 17

Polarization Voltage* V 0 0 0

Optimised Frequency Response 2 dB Hz 50 to 10 k 20 to 20 k 50 to 20 k

Dynamic Range with Preamplifier dB(A) to dB 32 to 134 28 to 140 32 to 134

Inherent Noise dB (A)

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Low-noise Microphones

Low-noise microphones are required for qualification

of anechoic chambers for sound power measurements and test

of components with low sound power ratings.

Type 4179 is suitable for monitoring very low background

noise levels down to 5.5 dB(A) and must be used with

dedicated preamplifier Type 2660 or 2660-W-001. This

combination has an unbeatable noise floor of 2.5 dBA

Type 4955is a 1/2-inch TEDS all titanium microphone with

an excellent noise floor of typically 5.5 dBA

Type 4955-A is a dedicated unit for sound level meters,

such as Types 2250 and 2270. It is optimized to work with

18 V

Type 4955-W-001 is a detachable unit for permanent

mounting with Adaptor UA-1260 in HATS

Type No. 4179 4955

Diameter inch 1 1/2

Optimised Low-noise Low-noise

Standards Nominal Open-circuit Sensitivity mV/Pa 100 1100

Polarization Voltage V 200 200

Optimised Frequency Response 2 dB Hz 10 to 10000 10 to 16000


dB(A) to dB 2.5 to 102

(2660)6.5 to 110(Built-in)

Inherent Nois e dB (A) 5.5* < 6.5

Capacitance pF 40 N/A

Venting Side Front

Lower Limiting Frequency (3dB) Hz 5 to 7 5


Temperature Coefficient dB/C 0.004 < 0.01


Preamplifier Included No Yes

TEDS UTID 116289Connector N/A LEMO 1B

* Cartridge alone, must be used with Type 2660 preamplifier and WH-3315 + WL-1302 With integral preamplifier

Every microphone has an inherent noise caused, amongst

other things, by Brownian movements. This results in a

noise voltage, which cannot be avoided even with the bestmicrophone. Low-noise TEDS Microphone Type 4955

consists of a high sensitivity cartridge, which has been

optimised for the lowest inherent noise. The graphs shows

the typical noise spectrum for Type 4955

20

1

1

B

10 00 1000 00 Hz LA
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Outdoor Microphones

Brel & Kjrs outdoor microphones are intended for permanent or

semi-permanent outdoor use. In addition to the obvious weather

protection, other features can be found with all Brel & Kjr

outdoor microphones, including calibration facilities, on-site remote

verification (CIC), and conformance with standards of special

importance such as IEC 61672, Electroacoustics Sound Level

Meters. This particular standard defines the requirements to the

directivity response of the microphone and is often overlooked or

misinterpreted.

Weatherproof Microphone Unit Type 4184 is for

permanent, semi-permanent and portable noise monitoring.

It features a probe type microphone for optimal protection

and directivity response plus both CIC facility and a built-in

acoustic sound source for verification

Outdoor Microphone Type 4198 is for semi-permanent

noise monitoring. Depending on circumstances, this well

protected microphone can sustain several months of

unattended use. Features CIC, a Falcon range microphone

and Outdoor Microphone Kit UA-1404

Outdoor Microphone Type 4952 has outer parts

constructed of carefully selected polymer materials making it

suitable for longer periods of unattended outdoor use (at least

one year service intervals). This microphone also features

CIC. The use of separate equalization filters enables Type

4952 to fulfil the requirements of IEC 61672 both for 0and

90of incidence

Outdoor Microphone Kit UA-1404 is for the protection of

your existing Type 4188, 4189, or 4190 microphones

All outdoor microphones are supported by a broad range of

accessories. Please refer to the Microphone Accessoriesfor an

overview.

Type No. 4184 4198 4952

Diameter inch Probe 1/2 1/2

Optimized Outdoor Outdoor Outdoor

Standards I, K I, K I, K

Nominal Open-circuit Sensitivit y mV/Pa 12.5 50 31.6

Polarization Voltage* V 200 0 0

Optimized Frequency Response 2 dB Hz 20 to 8000 6.3 to 16000 8 to 12.5 k

Dynamic Range with Preamplifier dB(A) to dB 25 to 140 15.2 to 146 15.8 to 146

Inherent Noise dB (A) 25 15.2 < 16

Venting Yes Rear Rear

Lower Limiting Frequency (3 d B) Hz < 20 2 to 4 1 to 5

Operating Temperature Range C 40 to 55 25 to 60 30 to 60

Temperature Coefficient dB/C 0.005 0.001 0.005

Pressure Coefficient dB/kPa 0.006 0.01 0.021

Preamplifier Included Yes Yes Yes

Connector B&K 7-pin LEMO 1B LEMO 1B

http://www.bksv.com/doc/Bp0741.pdfhttp://www.bksv.com/doc/Bp1696.pdfhttp://www.bksv.com/doc/bp2099.pdfhttp://www.bksv.com/doc/bp2099.pdfhttp://www.bksv.com/doc/Bp1696.pdfhttp://www.bksv.com/doc/Bp0741.pdf

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Laboratory Standard Microphones

The most used laboratory standard microphones are Types

4160(1) and 4180(1/2). These microphones have a well-definedcavity in front of the diaphragm and are optimised for use in

couplers and for maximum long term stability under reference

conditions. The proven long term stability is in the area of a few

mdB per year.

The most common way of performing primary calibration of

laboratory standard microphones is to use the reciprocity

calibration principle. Brel & Kjr offers the worlds most used

reciprocity calibration apparatus, that is, Type 5998 which is part

of Reciprocity Calibration System Type 9699.

Type No. 4160 4180

Diameter inch 1 1/2

Optimised Calibration Calibration

Standards G H

Nominal Open-circuit Sensitivity mV/Pa 47 12.5

Polarization Voltage V 200 200

Optimised Frequency Response 2 dB Hz 2.6 to 8000 4 to 20000Dynamic Range with Preamplifier(Preamplifier type number)

dB(A) to dB10 to 146

(2673)21 to 160

(2669)

Inherent Nois e dB (A) 9.5 18

Capacitance pF 55 17.5

Venting Side Side

Lower Limiting Frequency (3 dB) Hz 1 to 2 1 to 3


Temperature Coefficient dB/C + 0.003 0.002


Preamplifier Included No No

Measured stability of Brel & Kjr

Laboratory Reference Microphone Type 4180

over a 10-year period.

Note: 0.2 dB/division
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34/174Brel& Kjr Transducers28 www.bksv.com/transducers

SPECIAL TRANSDUCERS

Brel & Kjr also offers a range of special microphones,

including:

Low-frequency Microphone Type 4193 is designed to

measure infrasound, for example, in ship engine rooms, in

helicopters and in wind-buffeted buildings

Type 4189with UC-5265 brings the 3 dB limit of Hand-held

Analyzer Types 2250 and 2270 down to 1 Hz

Binaural Microphone Type 4101is designed especially forbinaural recording where testing on a human object is

preferred and/or the use of the traditional Head and Torso

Simulator (HATS) method is precluded

Probe Microphone Type 4182has a choice of probe tubes,

stiff or flexible, making it perfect for measurements in

awkward places

Impedance Tube Microphone Type 4187 is a 1/4

microphone specially designed for use in Impedance Tube

Kit Type 4206. The microphone features a non-detachable

protection grid which forms an airtight front cavity

Type No. 41934193 withUC-0211

4189 withUC-5265

Diameter inch 1/2 1/2 1/2Optimised Low-frequency Low-frequency Low-frequency

Standards E, K, M E, K, M B, I, L

Nominal Open-circuit Sensitivit y mV/Pa 12.5 2 50

Polarization Voltage V 200 200 0

Optimised Frequency Response 2 dB Hz 0.07 to 20000 0.13 to 20000 3 dB to 1 Hz


dB(A) to dB20.7 to 161

(2669)29 to 148

(2669)

Inherent Noise dB (A) 19 29

Capacitance pF 18 118 13

Venting Side Side Rear

Lower Limiting Frequency (3 d B) Hz 0.01 to 0.05

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35/174Special Transducers 29www.bksv.com/transducers

Transducers for Sound Intensity Analysis

The measurement of sound intensity provides information on

the magnitude and the direction of the sound energy in the

sound field. The measurement technique is used for a variety ofapplications such as the determination of sound power, sound

absorption and sound transmission. Sound intensity is

calculated from the quotient of the sound pressure and the

particle velocity; sound pressure can easily be measured

directly but the particle velocity is usually determined by a finite

difference approximation. This requires two phase matched

microphones in a face-to-face configuration. Brel & Kjr

provides a number of sound intensity probes that conform to

Class 1 in the Sound Intensity Instrumentation Standard,

IEC 61043, which describes the characteristics of microphone

pairs, intensity probes and calibration techniques for

intensity measurements.

PSI or dB?Traditionally acoustical engineers work in dBSPL defined

20 x log (pa/20mPa) where pa is the actual (dynamic) pressure

in pascals.

Pressure sensors often refer to PSI (Pounds per Square Inch).

It may be good to know that dB SPL can easily be converted to

pascal and after that to PSI.

1 Pa = 0.0001450 PSI and hence 1 PSI 6.9 kPa

Sound Intensity ProbesTwo sound intensity probes are available:

Type 3654for use with the sound intensity analysis system

based on Hand-held Analyzer Type 2270

Type 3599, suitable for use with sound intensity analyzers

based on PULSE

The main difference is that Type 3654 is based on a 10-pin

cabling system whereas Type 3599 is based on an 18-pin

cabling system and includes a remote control unit. The

acoustical specifications are the same as both use Sound

Intensity 1/2-inch Microphone Pair Type 4197 and Dual

Preamplifier Type 2683.

Type No. 4101 4101-A 4182 4187

Diameter inch 1/5 1/5 Probe 1/4

Optimised Binaural RecordingBinaural Recording with

TEDSProbe Pressure

Standards

Nominal Open-circuit Sensitivity mV/Pa 20 20 3.16 4

Polarization Voltage* V 0 0 200 200

Optimised Frequency Response 2 dB Hz 20 to 20000 20 to 20000 1 to 20000 1 to 6400

Dynamic Range with Preamplifier dB(A) to dB 23 to 134 23 to 134 42 to 164

Inherent Nois e dB (A) 23 23 42

Capacitance pF N/A N/A N/A 6.4

Venting Rear Rear Selected Rear

Lower Limiting Frequency (3 dB) Hz < 20 < 20 < 0.7

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Sound Intensity Microphone Pairs Dual Preamplifier

Type No. 3654 3599

StandardsIEC 61043

Class 1IEC 61043

Class 1

Microphones 4197 4197

Dual Preamplifier 2683 2683

Remote Control Unit ZH-0632

Spacer Length 6 to 200 mm 6 to 200 mm

Spacers Included

8.5 mm 250 Hz to 6.3 kHz 250 Hz to 6.3 kHz

12 mm 250 Hz to 5 kHz 250 Hz to 5 kHz

50 mm 20 Hz to 1.25 kHz 20 Hz to 1.25 kHz

Type No. 4197 4178

Diameter inch 1/2 1/4

Free-field FrequencyResponse 1 dB

Hz 5 to 12500 6 to 14000

Free-field FrequencyResponse 2 dB

Hz 0.3 to 20000 4 to 100000

Phase ResponseDifference (Abso lute Value)1/3-octave Cent re

Frequencies

< 0.05:20 Hz to 250 Hz

< f(Hz)/5000:

250 Hz to 6.3 kHz

1 kHz 20 kHz:0.1 f [kHz]

Ampli tud e ResponseDifference Norm alizedat 200 Hz

< 0.2dB: 20 Hz to1kHz

< 0.4dB: 20 Hz to7.1kHz

< 0.3dB: 100Hzto 10 kHz

< 0.5dB: 100Hzto 20 kHz

Accessori es Inc luded

8.5 mm Spacer:UC-5349

12 mm Spacer:UC-5269


6 mm Spacer:UC-0196


Polarized CapacityDifference

pF

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37/174Special Transducers 31www.bksv.com/transducers

Microphones for High-intensity Testing

Most noise measurements are limited to around 140 to 150 dB

maximum SPL, but applications such as measurement of

gunshots, airbag deployment noise, etc., require measurements

of dynamic pressure fluctuations corresponding to a SPL far

beyond 160 dB.*

For measurements below 110 dB, the condenser microphone will

normally be the preferred transducer, while above 200 dB

pressure sensors have to be used. In the intermediate range, you

can select between pressure sensors or condenser microphones.

Co

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